In the last time a number of illuminaires, or lights, used in hazardous areas were proposed, in which incandescent light sources or fluorescent light sources are replaced by light emitting diodes (LEDs). Such new light sources also have to meet the particular requirements for arranging such lights in hazardous areas, like a flameproof enclosure, or other requirements involved with explosion protected product like Ex-e, Ex-d and the like. Moreover, the light output of such LED light sources depends on the temperature and it might generally be said that any rise of ambient temperature from, for example, 20° C. to 90° C. will reduce the light flux from 100% to 50%. Therefore, cooling systems are necessary for such LED light sources which compensate the reduction in light flux. Also such cooling systems have to fulfil the requirements already mentioned above for the usage in hazardous areas.
One possibility to compensate the reduction in light flux, is to increase the cooling capacity of the complete fixture and corresponding housing of the light to at least partly compensate such reduction of light flux by increasing a contact surface with respect to the ambient atmosphere. Another possibility is to add some LEDs that are used in case there is a corresponding reduction in light flux.
However, those solutions will result in an increase of cost and also of size of the corresponding light or light fitting.